Panasonic Intellectual Property Management Co., Ltd.

Yoh Takano

Tetsuya Yamamoto

Shinichi Kohda

A switch circuit includes a first switch connected to a first node such that the first switch is connected in series between the first node and a first electrode terminal of a DC power source. a second switch connected in series between the first node and a second node which is configured to be connected to a second electrode terminal of the DC power source, a soft switch circuit, a power switching element, and a controller. The soft switch circuit includes a capacitor connected in series between a third node and one of the first and second nodes, a charge-discharge switch connected in series between the third node and another of the first and second nodes, and a charge-discharge resistor connected in parallel to the charge-discharge switch. The power switching element has a drain terminal, a gate terminal connected to the first node, and a source terminal connected to the second node. The controller turns off the first switch, turns off the second switch, and switches the charge-discharge switch from turning off of the charge-discharge to turning on of the charge-discharge at a time point when the controller detects that a current flowing across the drain terminal and the source terminal of the power switching element is equal to or larger than a predetermined threshold while the first switch is turned on.

Switch circuit

A light-receiving circuit receives light emitted by a light-emitting part and generates an energization signal that is an electric current based on intensity of the light. A hold circuit is configured to supply an electric charge of an energization signal to a high electric potential terminal and not to decrease a voltage of the high electric potential terminal in a case where a control circuit is sending an OFF signal. Furthermore, the hold circuit is configured not to supply the electric charge of the energization signal to the high electric potential terminal and to keep the voltage of the high electric potential terminal in a case where the control circuit is sending an ON signal. A comparison circuit compares a comparison signal and a reference signal, generates a bias voltage based on a result of the comparison between the comparison signal and the reference signal, and feeds back the bias voltage as a reference signal. A driving circuit supplies the bias voltage to a reference terminal while the control circuit is sending the OFF signal.

Power conversion circuit

A power conversion device includes a switching element, a gate drive unit, a switch circuit unit, a DC power supply unit, and a control unit. The control unit controls a plurality of switch circuit units and a plurality of gate drive units. During a normal period, the control unit causes a first switch and a second switch to be closed, and causes a signal from the gate drive unit to continue a high level or a low level. Furthermore, during a switching period, the control unit causes the first switch and the second switch to open, and switches a signal from the gate drive unit from a low level to a high level or from a high level to a low level.

Power conversion device and power supply device in which same is used

A gate driver that drives a field-effect transistor on the basis of an input signal includes a comparator that compares an applied voltage applied between the drain and the source of a field-effect transistor to a reference voltage for detecting noise occurring between the drain and the source of the field-effect transistor, and a gate voltage switching circuit that, if the field-effect transistor is off, switches the voltage applied between the gate and the source of the field-effect transistor from a first voltage to a second voltage when the output of the comparator transitions from a state indicating that the applied voltage between the drain and the source is less than the reference voltage to a state indicating that the applied voltage between the drain and the source is equal to or greater than the reference voltage.

Gate driver and power module equipped with same

Disclosed is an inverter having improved power conversion efficiency. The inverter () converts direct current power supplied from a plurality of direct current power supplies (V, V) having different voltages into alternating current power. The inverter () is provided with a control unit (). The control unit () generates modified sine waves using a power supply voltage (E) of the power supplied from the first direct current power supply (V), a power supply voltage (E) of the power supplied from the second direct current power supply (V), and a potential difference (E&#x2212;E) between the two power supply voltages. The control unit () generates the modified sine waves by controlling H bridge circuits provided for the direct current power supplies (V, V), respectively.

Inverter and power converter having inverter mounted therein

A comparator compares a voltage of a node into which electric current flows from a system of a first voltage and a reference voltage for maintaining the node at a second voltage. A step-up-type DC-DC converter receives the voltage of the node which is input to the comparator, increases the voltage to a voltage higher than the first voltage, and applies the voltage to the system of the first voltage. According to the comparison of the comparator, when the voltage of the node is higher than the reference voltage, the step-up-type DC-DC converter activates a step-up function, and when the voltage of the node is equal to or less than the reference voltage, the step-up-type DC-DC converter deactivates the step-up function.

Growing community of inventors

Fukushima, Japan

Yoh Takano